Internal-combustion engine



- Aug. 3 1926. 1,594,773

L. O. FRENCH INTERNAL: COMBUSTIQN ENGINE Filed May 29l 1924 I N VEN TOR.

ZMM.

Patented Aug. 3,

UNITED STATES v LoUIs o. FRENCH, or MILWAUKEE, WIscoNsnr.

rNTEnNALcoMBUs'rI-ON ENGINE.

Application Med May 29, 1924. Serial No. 716,687.

. The invention relates to internal combustion en nes, and more particularly to those using llquid fuel.

In engines which are now quite commonly known as gas injection type internal combustion engines, the passage of fuel from *.Ih'ead and associated the fuel-receivin chamber cannot =be readily controlled, andr especially those engines in which the fuel in a liquid state is introduced into a fuel-receiving chamber during the suction stroke of a four-cycle engine, or during the scavenging period of a two-cycle engine. The object of this invention is to. rovide an internal combustion engine of t e gas injection type of improvedconstruction over those heretofore known, by delaying the introduction of the fuel charge into the cylinder after its passage from the fuel-receiving chamber, and to mix the main fuel charge with gas as it passes to the cylinder, and to utilize some of the fuel charge either under conditions of constant volumeY combustion or mixed combustion to assist in the expulsion of the charge to the cylinder, the action 'of the gas assisting in vaporizing such fuel as may issue from the fuel-receiving chamber in a liquid state.

A .further object of theinvention is ,to provide a gas injection type engine that may be run on more volatile fuels, such as gasoline y.or its substitutes, than are usually 'employed with engines of this general type,

and under medium or low compression pressures, with such provision for stratification of the fuel charge as to prevent detonation and secure elicientcombustion at constant volume.

The invention further consists in the several 'features hereinafter set forth and more particularly defined by claims at the conclusion hereof. n

ln the drawings: Fi 1 is a vertical sectional view taken on t e line I-l of Fig. ,2 through an engine embodying the invention; 'l

Fig. 2 is a plan view of the cylinder arts.

ln the drawings t e numeral 3 designates the cylinder 'of the engine, 4 the piston working therein, 5 the c linder head with the waterjacket s ace 6, the main combustion chamber, 8 a giel-receiving chamber, 9 a gas chamber, .l0 a mi4 g passage with which chambers 8 and Q communicate, 1l a fuer i control valve, 12 the main air inlet valve,

and 13 the exhaust valve, said last-named valves being used where the engine is fourcycle.

The fuel-control valve 11 is mounted in a plug 14 having screw-threaded engagement with the cylinder, a pipe threaded connection being here shown, to permit ready removal of the plug from the cylinder and providing a seal when mounted in the cylinder head. The valve 11 controls the passage of fuel from a duct 16 in the plug to the chamber 8. The duct communicates with a passage -17, the flow of fuel from the passage 17 to the passage 16 being controlled by an adjustable needle valve 18 having screw-threaded engagement with the -upper end of the plug, and either manually or governor-operated. The duct passage 17 is supplied with fuel )from a fuel tank, not 19 connected with said tank, said fuel being either under gravity head or under a slight pressure heady rfrom gas pressure in the tank.

The inlet and exhaust valves are of wellknown construction normally closed by springs 20 and opened by suitable valve gear such as tappet levers 21 operated by push-rods -22 from a halftime cam shaft, not shown.

The fuel-control valve 11 also preferably controls passage of some air into the chamber 8 from a passage 23. In case of a fourcycle engine this `duct leadsto atmosphere, as shown, and in a two-cycle engine it may connect with the scavenging air supply. This valve isl normally held closed by a spring 24 and may be of type, opened either by suction pressure in the four-cycle or by the scavenging/p ressure in a two-cycle en e posime. It may also tively operated urin the 'suction stroke shown, through\a pipe the automatic inlet A of the fourcycle or t escavenging stroke of a two-cycle engine lby a suitable valve mechanism of any well-known form of overhead valve gear. As shown( in connection with the four-cycle engine, the valve is acntuated by a lug 25 on the tappet lever 21 for the inlet valve with a screw 26 o said lug and engageable with the valve and adjustable re ative to said lug to permit relative adjustment between the lever and said valve to vary the timing operation of the Ivalve '11 relative to the inlet valve 12, if desired.

The chamber Sois in restricted communication with' the passage l@ and preferably at the upper endA thereof through oneaor more passages 27,- preferably relatively small but not necessarily so fine as to be relied upon for atomizing purposes since the action of the as in the mixing passage causes a breaking up of the fuel clrarge should some of it issue from the chamber 8 'in a liquid' state.

The end of the passage 10 is preferably in restricted communication with thefcombustioif chamber through one or more openings 28, though in some instances said end may be left 1n open communication with the chamber 7. As shown, the openings 27 and 28 are formed in a tube 29 having a close fit with the adjacent walls of the head, to prevent excessive heating, and a threaded connection with said head at its vlower end. The passage 10 throughout its length, as well as its lower end, may be water-cooled, if desired. The passage 10 may take the form of a Venturi passage with the passages 27 may be drawn into introducing the fuel charge into the throat portion thereof, as shown, said'throat being preferably located adjacent thechamber 9.

Where volatile fuel is used as the main fuel or as a starting fuel for the engine, a sparking ignition device 30 is mounted in the chamber 9.l Where less volatile fuels are used an incandescent ignitor of the hot surface or hot electric wire type may be used either in the chamber 8 or the chamber 9, or a portiony of the surface of the chamber 9 may be uncooled.

The chamber 9 is here shown formed as a part separate from the cylinder head and bolted thereto, and said part is also recessed and forms with the 'tube 27 and a part of the main cylinder head the chamber 8, though said chambers 9 and 8 may be formed integrally with the cylinder head, if

desired.' v

Assuming that lthe engine has been started and a volatile fuel is being used, during a period of low pressure in the engine cylinder, that is 'during the suction stroke of a fourcycle or the scavenging period of a twocycle engine, -the valve 11 is opened allowing fuel to flow from the duct 16 to the chamber 8, as well as some air from the passage 23. During the suction stroke some of the fuel in a gaseous state, due to its contact with hot gases from a previous cycle andits mixing with the air let in through passage 23 when such passage is provided, the passage 10 where it contacts with more inert exhaust gases and during the compression stroke is forced up into the chamber 9 lwhile the remainder of the fuel is in the chamber 8. .As compression roceeds air from the cylinder is forced up into the assage 10 and into the chambers 8 and 9 an near or at the end of the compression stroke'y when an-explosive mixture has been formed in the chamber 9 the spark from chamber, and as the hot flaming gases from "the chamber 9 pass down through the the ignition device 30 i nites said mixture and the consequent exp osion builds up a pressure therein, due to the restricted outlet, greater than that in the'main combustion passage 10 atv relatively high velocity, they encounter fuel coming in from the chamber 8 and mix and pass therewith through openings 28 into the main combustion chamber as the piston starts on its downward stroke. Thereafter combustion of the fuel charge introduced into the air in the cylinder becomes general with the expanding gases driving the piston downward on its power stroke. Furthermore, the suction effect ofthe piston accentuates the difference in pressure between the main combustion chamber 7 and the other parts 8, 9 and 10 and acts to draw the fuel from the chamber 8 into the hot gases from the chamber. This last 'condition may be especially the case with a two-cycle engine, as there may be only a small amount of. fuel that reaches the chamber 9 durin the compression stroke. However, in either case the building up of pressure in the chamber 9 by the urning of gases therein causes some of the hot gases issuing therefrom to enter the chamber 8 and act to vaporize or gasify the fuel therein, and should the expansion of the gases in the chamber 8 drive some of the fuel in a liquid state into the passage 1 0, 'the' hot gases coming from the chamber 9 will act to vaporize such liquid fuel, either'completely' orto a great extent, before its passage to the cylinder.

vThe advantage of the restriction between the passage 10 and the main combustion chamber is. that it permits the ready retention of relatively inert gases in the chamber 9 and passage 10 and thereby retards active combustion until late in the compression stroke, and it also retards the relatively free passage of air to the chamber 9 during the com ression stroke to thereby retard active com ustion until desired, and it also aids the mixing action and distribution of the fuel charge into the air in the main combustion chamber.

Thus,lin,the case of a volatile fuel using low or medium compression pressures, the fuel introduced into the chamber 8 before compression begins is vaporized and mixed with air and heated by inert gases before passing into the main combustion chamber near or at the end of the compression stroke. With medium compression pressures Iess volatile fuel may be used after the engine has become heated, because then the air underoing compression is itself brought to a lg'iigher temperature and serves to break down some of the lighter constituents of the fuel i in the chamber 8 which acts as a volatile fuel charge in the manner previously described, 180

and upon the remainder of the fuel to gasify and discharge it into the cylinder at or near the beginning of the working stroke.

When high compression pressures are used the heat of the air alone is used to effeet a gasification of some of the fuel in the chamber.' 8. As said chamber 8 is Watercooled, for the most part, gasification of the fuel will not be as rapid as in engines heretofore known so that there is less danger of detonation occurring in the main combustion chamber, such fuel as is gasified, however, acting in the manner of the volatile fuel, as previously described, to vaporize, expel and mix the remainder of the fuel charge and discharge it through the passage 10 and dll openings 28 into the main combustionl chamber at or near the beginning of the working stroke.

The inlet and discharge of air and exhaust gases from the cylinder space takes place through the valves 12 and 13 in the usual manner, and through valves or ports in a two-cycle engine inany suitable manner.

It will also be noted that the rate ofk passage of the fuel charge from the chamber 8 into the passage 10 may be regulated byselection of the proper discharge area provided by the hole or holes 27, and that the amount of gaseous fuel to the amount of air or other gas passing through the passage 10 may be determined by the rate of discharge from the chamber 8 'and the cross-sectional area-of the throat portion of the passage 10.

The construction above described permits of a gradual mixing of the fuel charge with the gas passing to the cylinder, and this permits of a proper proportion of fuel to air at dierent loads, and a mixture may be formed at light loads and 'eiciently consumed in an excess of air.

l desire it to be'understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are included in the claims or necessitated by the prior art.

What l claim as my invention is l. lin an internal combustion engine, the combination with the cylinder space, of a fuel-receiving chamber, a gas chamber, a mixing passage constantly communicating with said gas chamber and in continual directrestricted communication` with said fuelreceiving chamber and leading to said cyly inder space, means for supplying air to said cylinder space, and means distinct Vfrom said first-mentioned air supply means for intro- .ducing fuel into and supplying air to said fuel-receiving chamber begins.

2. In an internal combustion engine, the combination with the cylinder space, of a fuel-receiving chamber, af gas chamber, a mixing passage constantly communicating efore compression with said gas chamber and in continual direct restricted communication with said fuel-receivingv chamber, said mixing passage extending to said cylinder space, a nozzle member at the inner end of said mixing passage, means for supplying air to said cylinder space, and means distinct from said firstmentioned air supply means forrsupplying fuel and air to said fuel-receiving chamber before compression begins.

3. In an internal combustion engine, the combination with the cylinder space, of a fuel-receiving chamber, a gas chamber having a Venturi discharge passager leading therefrom to the cylinder space, said fuelreceiving chamber having a discharge passage in communication with the throat portion of said Venturi passage, means for supplying air to said cylinder space, and means distinct from said first-mentioned air supply means for supplying fuel and air to said fuel-receiving chamber before compression begins.

4. In an internal combustion engine, the combination with the cylinder space, of a fuel-receiving chamber, a gas chamber having a Venturi discharge passage leading therefrom to said cylinder space, a discharge nozzle at the inner end of said passage, said fuel-receiving chamber having a dis- -charge passage in communication with the throat portion of` said Venturi passage, means for supplying air to said cylinder space, and means distinct `from said firstmentioned air supply means for supplying fuel and air to said fuel-receiving chamber before compression begins.

5. In an internal combustion engine, the combination with the cylinder-space, of a fuel-receiving chamber, a gas chamber, a mixing passage constantly communicating with said gas chamber and in continual direct restricted communication with said fuel-receiving ,chamber and leading to said cylinder space, and means including a valve opening inwardly into said fuel-receiving chamber for controlling the passage of fuel thereto. Y

6. In an internal combustion engine, the

combination with the cylinder space, of a fuel-receiving chamber, a gas chamber, a mixing passage constantly communicating with said gas chamber and in continual direct restricted communication with said fuel-receiving chamber and in communication with said cylinder space, a discharge nozzle at the inner end of said passage, and means including a valve opening inwardly into said fuel-receiving chamber for controlling the passage of fuel thereto.

t .In testimony whereof, li aix my signaure.

Louis o. FRENCH. ,y 

